Multimodal Affinity-Modulated Efficient Separation of Lysozyme with a Hierarchical MXene@MOF Hybrid Framework

The development of abiotic protein affinity adsorbents remains challenging for the accurate acquisition and analysis of specific protein species. Inspired by bacterial cell walls, a hierarchical hybrid framework is fabricated through the oriented growth of an Fe-based metal organic framework (MOF) on V₂C MXene for the efficient separation of lysozyme (Lys). After directed evolution of adsorptive materials, the MXene@MOF composite rich in hydroxyl groups (termed as MX@MOF-DH) is found exerting exceptional affinity for Lys. Benefiting from hydrogen-bonding, coordination, and electrostatic interaction-mediated multimodal and multivalent affinity, MX@MOF-DH reveals rapid adsorption rate (5 min), superb enrichment factor (83.1), and favorable binding capacity (609.7 mg g^-1), which outperforms other latest adsorbents. Moreover, femtomolar sensitivity is achieved even in the presence of high-abundant interfering proteins, as confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometer analysis. This work not only provides an efficient approach for selective enrichment of lysozyme but also paves an avenue to construct the protein affinity reagents for specific biological medicine and analysis applications.